Reflecting on a Multi-Year Conservation Biological Control Project

While the Xerces Society is well-known for its work on pollinator and endangered species conservation, there are also, beyond these organisms, many beneficial insects. In agricultural lands and gardens, beneficial insects like predatory beetles and parasitoid wasps can provide a form of natural pest control called conservation biological control (CBC). Over the past four years, the Xerces Society has embarked on a nationwide project to promote these beneficial insects in our agricultural landscapes, and it was my pleasure to take the helm for this work.

Thelma Heidel Baker, Xerces Society Conservation Biological Control Specialist, (right) presents a CBC course in Arkansas. Over the course of four years, Thelma facilitated a series of 61 day-long courses in 49 states. (Photo: Shaun Francis / University of Arkansas)

From 2015–2019, a series of 61 day-long courses were presented in 49 states, which enabled the Xerces Society to bring these beneficial insects back into the conversation on pest control and expand the dialogue beyond just insecticides and other pesticides as a viable pest management tool. The courses were jam-packed with relevant topics ranging from impacts of farmland management practices (tillage, cover crops, etc.) and pesticide risk mitigation to habitat creation and plant selection. Many courses also included several hours of field activities where course participants were able to experience insect scouting first-hand and learn how to conduct a farm habitat assessment for beneficial insect conservation.

The CBC short courses were extremely successful and highly regarded by attendees for their utility and practical recommendations. Over the four-year period, nearly 2,000 people enrolled in the courses, averaging 30 people per event. The course was developed for farmers and agency staff (government and university, primarily) who work with farmers, but the audience was often much broader, frequently including scientific researchers, master gardeners, and homeowners. In particular, over 600 USDA NRCS staff from the 49 states where courses were offered attended the courses.

Participants in a conservation biological control course in Caldwell, Idaho. Over the four years of the program, nearly 2,000 people enrolled in the CBC courses, averaging 30 people per event. (Photo: Justin Ross / NRCS)

Let’s take a step back, though: Who are these beneficial insects providing natural pest control?

They are an extremely diverse community of insects, ranging from the familiar lady beetles (family Coccinellidae) to the tiny insidious flower bugs (Orius insidiosus)and voracious lacewing larvae (order Neuroptera). Some are predators that feed directly on other insects and some are parasitoids that lay their egg(s) inside other insects. Some are specialists with a preferred prey type (stinkbug eggs, for example), while others have a broader palate, eating whatever comes their way. These beneficial insects also include all wasps, because wasps—yes, even yellowjackets!—are all insect predators in some stage of their life cycle.

Here at the Xerces Society, we often refer to them as beneficial insects, but in other contexts they may also be called natural enemies or biological control agents. Not surprisingly, the diversity within this insect community lends them to need a diversity of habitat and food resources to support themselves.

The term “beneficial insects” spans a wide array of species of predators and parasitoids, all of which help to reduce populations of crop pests, and can be harnessed through conservation biological control. Pictured, left to right: An assassin bug with its stink bug prey (Xerces Society / Nancy Lee Adamson); a pink spotted lady beetle (Coleomegilla maculata) (Xerces Society / Thelma Heidel Baker); and a six-spotted tiger beetle (Cicindela sexguttata), a predator known for its speed (Xerces Society / Sarah Foltz Jordan).

Spurred by these beneficial insect short courses going on throughout the country, several new conservation biological control resources were created. This includes a fantastic conservation guide calledHabitat Planning for Beneficial Insects, complete with excellent photos, descriptions, and practical conservation strategies for many different beneficial insects. ABeneficial Insects for Natural Pest Control Scouting Guide serieswas also developed to provide guidance on how to look for predatory and parasitoid insects in habitat areas. These tools use simple protocols and readily available materials (clipboard, white paper, cups, etc.) for people to build a familiarity with this community of beneficial insects in their cropland, established habitat areas, or even backyards.

We are already reaping the broader benefits of offering these courses and creating an awareness of conservation biological control. 2,000 farmers were trained in the initial conservation biological control courses, and due to post-course reporting, we know that agency staff have carried the message forward to an additional 1,700 farmers—a ripple effect that we hope continues. To date, over 3,900 acres of habitat have been created on farms. Many farmers have changed management practices—by incorporating flowering cover crops, reducing tillage, and so on—on 12,733 acres of farmland specifically to support beneficial insects. The conservation biological control courses have also resulted in 58 farms enrolling in USDA NRCS conservation programs to protect beneficial insects.

The grant for the Xerces Society conservation biological control courses may have ended, but their vital lessons on supporting beneficial insects can still spread. It is now up to farmers and agency staff to carry this torch forward. (Photo: Xerces Society / Thelma Heidel Baker)

With time, these numbers will continue to increase as the importance of beneficial insects and their relevance to agricultural pest management is recognized. In fact, the framers of the 2018 Farm Billrecognized the value of these important insects and designated them as an important research priority for USDA research grants over the next five years.

Although the grant for this particular program recently ended, we are hopeful that this message will continue to spread. It is now up to farmers and agency staff to carry this torch forward—and we are grateful to those who have already implemented changes that support beneficial insects.

Written by Thelma Heidel-Baker, Xerces Society Conservation Biological Control Specialist.

Funding for this work was provided by grants from all four of the Sustainable Agriculture Research & Education (SARE) Program regions (Northeast, North Central, Southern, and Western).